1. Field of the Invention
The present invention relates to a focal length switchover camera capable of selectively carrying out standard photography and telephotography, or standard photography and a wide-angle photography, or camera with an attached zoom lens capable of carrying out photography with its focal length being steplessly varied, and more particularly to a camera of the above type having focal length switchover means for switching over a focal length of a photographic optical system by moving a lens barrel holding the photographic optical system in a direction of an optical axis relative to a camera body and a lens barrier for opening and closing a front face of the lens barrel to protect the photographic optical system.
2. Description of the Prior Art
In the case of a conventional camera of the above-described type, the lens barrier is provided inside the lens barrel together with the photographic optical system. However, such a camera has drawbacks to be described hereinafter.
In the case of the camera having the lens barrier inside the lens barrel, it is necessary to dispose inside the lens barrel an opening-closing mechanism for opening and closing the lens barrier. Thus, the lens barrel tends to have a large radius. Moreover, since this lens barrel is to move along the optical axis relative to the camera body, it is also necessary to reserve sufficient space to permit the movement of the large-radius lens barrel. As a result, other components must be inconveniently disposed in the camera.
Furthermore, since the weight of the lens barrel necessarily increases as the lens barrier and the opening-closing mechanism are integrated therein, a mechanism for carrying out the focal length switchover tends to be large and complicated. This causes further inconvenience in the disposition of other components and increases cost as well.